fig3

Figure 3. (A) N₂ adsorption-desorption isotherms of Ni₃N-Co₂N_0.67/NC and N₁C₂-TEOA (Inset: pore size distribution pattern). High-resolution XPS spectrum and simulation of (B) Ni 2p, (C) Co 2p and (D) N 1s for Ni₃N-Co₂N_0.67/NC.